A patio that looked fine in summer can turn green over autumn and winter. It isn’t only about looks. Green growth makes paving slippery.
What the green is
The green film on patios is usually algae. It grows on damp paving that doesn’t get much sun. Moss can follow, especially in joints and on the edges of slabs.
Why some patios are worse
- Shade. Patios next to fences, walls or trees stay damp for longer.
- Poor drainage. Water that sits on the surface feeds growth.
- Porous stone. Some natural stones and older concrete slabs hold moisture.
- Dirt and leaves left on the surface.
The slip risk
Wet algae is slippery. Paths and patio steps that go green are a real risk, particularly for children and older people. Cleaning them before winter is worthwhile.
Getting it clean
Patios are pressure washed to remove dirt, algae, moss and built-up grime. A cleaning treatment can be used where needed for a longer-lasting finish, and paving can be re-sanded afterwards where suitable.
Keeping it clean
- Sweep off leaves and soil.
- Cut back plants that shade the patio.
- Make sure water can drain off rather than sitting in puddles.
Black spots that don’t shift with washing are usually lichen, not dirt. See black spots on paving.
See patio cleaning or ask for a quote.
